so basically the crash is due to NVIDIA driver?

Well; I myself have random crash on ATI; that bcoz I overclock the 5770 to 940Mhz from default 850Mhz... the solution was simple; set the FAN speed to manual (90%); seems the threshold is to get the gfx stable is to have below 85dC; even using a big HAF-X chassis not good enough on airflow